x64 vs x86

Just wondering what the difference is between these two versions. I have Windows 7 x64, but have always downloaded the x86 version because it says, "Recommended" on your download page. But then I noticed in one of the recent threads
here that there is a bug in the latest x86 version and that the x64 version hasn't been affected. Why do you recommend the x86 version over the x64 one? Besides this current problem, is the x86 version generally more stable than the x64?
All things being equal, assuming no current bugs, what kind of differences might I see between the 2 versions?

The way Codeplex works is you have one "recommended" download that starts when you hit the big download button on the main page, and then other downloads that you can get if you go to the specific download page. I choose x86 for the recommended download
because it will work on both x86 Windows and x64 Windows. That is, they'll always get something that works when they click the big green button.

About the bug: I'm not even sure it's x86 vs x64 anymore. It seems to be related to the phases of the moon. :( I think closed captioning is broken on x64 but that's the only difference I know of.